Somewhat relevant previous discussion: "We should have markdown rendered websites": https://news.ycombinator.com/item?id=33548134
I think a major pro of browsers serving content in a limited markup language (with Gopher being the extreme example) is that a variety of applications can realistically work with rendering them, without having to offload everything to a web browser.
I've been wanting to write a simple markdown renderer so that I can view my notes/todo in a nicer form without having to generate a PDF or open by browser, so I'm very excited to take a look at this codebase later.
I couldn't help but think of Gemini[0,1] and the number of applications already built for it[2] precisely because of the limited language. Gemini is an exciting space for lovers of a safer and lightweight internet.
It becomes clear that when rendering (and feature-bloat) are reduced, development begins to thrive. The Lagrange browser[3] is a great example of rendering not being an issue which gives developers time to build a great browser. For anyone curious, check it out to see what I mean: portable versions are available on Windows and Linux (appImage).
I have to admit that textual-markdown (OP) has me feeling the same way. I've been using command line browsers (on/off) for decades (since DOS). I don't know if I've ever seen a text-based browser look so beautiful. Wish the author the motivation and passion to keep this project going. I think it has great potential.
[0] https://gemini.circumlunar.space/
[1] https://en.wikipedia.org/wiki/Gemini_(protocol)